一类古典概型的公式解

针对一类古典概型,通过将基本事件数转化为不定方程的解的个数,并利用组合方法将其求出,进而可以得到该古典概型的公式解.     

二维等熵可压欧拉方程古典解的存在性(英文)

研究二维等熵可压缩欧拉方程的古典解存在性.利用迭代技巧,得到解的局部存在性及唯一性,并且还证明了解在有限时间内爆破,即可压缩欧拉方程不存在全局古典解.     

一类含有p-Laplacian算子的脉冲微分方程解的存在性和多重性

本文研究一类含有p-Laplacian算子的二阶脉冲微分方程边值问题解的存在性和多重性.当脉冲函数满足超线性增长条件时,我们通过变分法证明该问题至少存在一个古典解和无穷多个古典解.     

一类具交错扩散的强耦合退化抛物方程组解的整体存在与非存在性

本文研究了一类具交错扩散的强耦合拟线性退化抛物方程组初边值问题正古典解的局部存在,整体存在与非整体存在性.利用正则化方法和先验估计技巧证明了该问题正古典解的局部存在性,并且分别给出了该问题是否存在整体古典解的充分条件.结果表明当种群内竞争强于种群间互惠作用时,此问题存在整体解;而当两种群具有强互惠作用时,所有解都是非整体的.     

二阶半线性椭圆方程的径向解

本文讨论了无界域上的二阶半线性椭圆方程的径向解，给出了古典解的性质，诸如存在或非存在性，唯一性以及解的估计式等，这些性质清晰地描绘了古典解的性态。     

一类周期自由边界问题解的渐近性态

本文证明了化学反应扩散过程中的一类周期自由边界问题古典解的存在唯一性，并且讨论了潜热L→0时周期Stefan问题古典解的渐近性态及误差估计．     

平面二阶偏微分方程组的边值问题

本文讨论偏微分方程组(1)的边值问题的提法,证明条件(D)是保证在任何有限域上边值问题(1),(2)的古典解唯一的充要条件.当条件(D)成立时,证明了广义解的存在唯一性,并举出古典解存在的一些例子.     

源于DNA的非线性波动方程组的Cauchy问题(英文)

本文首先证明源于DNA的非线性波动方程组的周期边值问题局部古典解的存在性和唯一性.其次通过周期边值问题序列证明这个方程组的Cauchy问题存在唯一的局部古典解.     

一类半线性积分微分方程初值问题之整体解的存在性与唯一性

本文运用能量廷拓方法,讨论了一类描述有内部热耗散的杆中热传导问题的半线性积分微分方程初值问题之整体古典解的存在性,并附带证明了该问题之古典解的唯一性。     

具有非线性扩散项的多维趋化趋触模型的整体有界性

本文主要研究一类带有齐次Neumann边界条件且具有非线性扩散项的趋化趋触模型,在较宽的条件下,证明了系统具有整体有界古典解.推广了XU等(2019)和JIA等(2020)得到的整体有界的古典解的结论.     

Multiple and sign changing solutions of an elliptic eigenvalue problem with constraint

We prove the existence of sign changing solutions of a semilinear elliptic eigenvalue problem with constraint by using variational methods. Among those three solutions we obtained, one is positive, one negative and one sign changing. We also prove the existence of multiple sign changing solutions under some additional condition.     

Mathematics

We prove the existence of sign changing solutions of a semilinear elliptic eigenvalue problem with constraint by using variational methods. Among those three solutions we obtained, one is positive, one negative and one sign changing. We also prove the existence of multiple sign changing solutions under some additional condition.     

Periodic non-autonomous second-order dynamical systems

We study the existence of periodic solutions for a second-order non-autonomous dynamical system. We give three sets of hypotheses which guarantee the existence of non-constant solutions. We were able to weaken the hypotheses considerably from those used previously for such systems. We employ a saddle point theorem using linking methods.     

Global existence of weak and classical solutions for the Navier-Stokes-Vlasov-Fokker-Planck equations

We consider a system coupling the incompressible Navier-Stokes equations to the Vlasov-Fokker-Planck equation. The coupling arises from a drag force exerted by each other. We establish existence of global weak solutions for the system in two and three dimensions. Furthermore, we obtain the existence and uniqueness result of global smooth solutions for dimension two. In case of three dimensions, we also prove that strong solutions exist globally in time for the Vlasov-Stokes system.     

Existence of three positive solutions for a class of Riemann-Liouville fractional q-difference equation

In this paper, we confirm the existence of three positive solutions for a class of Riemann-Liouville fractional $q$-difference equation which satisfies the boundary conditions. We gain several sufficient conditions for the existence of three positive solutions of this boundary value problem by applying the Leggett-Williams fixed point theorem.     

EXISTENCE OF TRIPLE POSITIVE SOLUTIONS TO A MULTI-POINT BOUNDARY VALUE PROBLEM

We apply a fixed point theorem to verify the existence of at least three positive solutions to a multi-point boundary value problem with p-Laplacian. Existence criteria which ensure the existence of triple positive solutions are established.     

On the existence of three solutions for the Dirichlet problem on the Sierpinski gasket

We apply a recently obtained three-critical-point theorem of B. Ricceri to prove the existence of at least three solutions of certain two-parameter Dirichlet problems defined on the Sierpinski gasket. We also show the existence of at least three nonzero solutions of certain perturbed two-parameter Dirichlet problems on the Sierpinski gasket, using both the mountain pass theorem of Ambrosetti and Rabinowitz and that of Pucci and Serrin.     

On the existence of global weak solutions for Vlasov-Poisson-Fokker-Planck systems

This work studies the question of global existence of weak solutions to Vlasov-Poisson-Fokker-Planck equations with spatial, or momentum, dimensions greater than, or equal to, three. We define a concept of weak solutions to these equations and show (i) global existence for plasma physical models with spatial (or momentum) dimensions greater than or equal to three, and (ii) global existence in three spatial dimensions with arbitrary data for the stellar dynamical case.     

Stability of two‐dimensional magnetohydrodynamic motions in the periodic case

We investigate the stability of two‐dimensional periodic solutions to magnetohydrodynamics equations in the class of three‐dimensional periodic solutions. We show the existence of global, strong three‐dimensional solutions to magnetohydrodynamics equations, which are close to two‐dimensional solutions. The advantage of our approach is that neither these solutions nor the external forces have to vanish at infinity. Copyright © 2015 John Wiley & Sons, Ltd.     

A boundary value problem associated to non-homogeneous operators in Orlicz-Sobolev spaces

We apply a three critical points theorem of B. Ricceri to establish the existence of at least three weak solutions for a class of non-homogeneous Neumann problems. Furthermore, by using another theorem of him, we prove that an appropriate oscillating behaviour of the nonlinear term ensures the existence of infinitely many weak solutions. Our analysis is based on recent variational methods for smooth functionals defined on Orlicz-Sobolev spaces.